Last night I was surfing the 5 MHz segment, when I heard a station sending 5 letter groups, in Spanish, USB, at 5155 kHz. I thought it was a Number Station, but this time there was another station acknowledging the transmissions.

The station PN (Papa November) was reading out the groups, and San Pedro Radio-CBS (Chilean Coastal Station) was confirming reception, or asking for repeats. This went on for about 30 minutes, with ocasional log-ins by Magellanes Radio-CBM (also Chilean Coastal Station).